During a Devastating Flood, the Crew of a Rescue Helicopter

During a devastating flood, the crew of a rescue helicopter saved Muriel. Within seconds of being plucked from the roof of her home, she watched as the floodwaters destroyed her home. Since the catastrophe, she has been irritable and anxious and has had flashbacks of the event. She is probably suffering from:

A) posttraumatic stress disorder.
B) dissociative disorder.
C) obsessive-compulsive disorder.
D) dementia.